BKTSX vs. FSKAX

Last updated Jun 3, 2026

BKTSX (iShares Total U.S. Stock Market Index Fund Class K) and FSKAX (Fidelity Total Market Index Fund) are both Large Cap Blend Equities funds. Over the past 10 years, BKTSX returned 15.11%/yr vs 15.07%/yr for FSKAX. With a 1.00 correlation, they move nearly in lockstep. BKTSX charges 0.02%/yr vs 0.01%/yr for FSKAX.

Performance

BKTSX vs. FSKAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Total U.S. Stock Market Index Fund Class K (BKTSX) and Fidelity Total Market Index Fund (FSKAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both investments are quite close, with BKTSX having a 11.47% return and FSKAX slightly higher at 11.81%. Both investments have delivered pretty close results over the past 10 years, with BKTSX having a 15.11% annualized return and FSKAX not far behind at 15.07%.

BKTSX

• 1D: 0.23%
• 1M: 5.02%
• YTD: 11.47%
• 6M: 11.82%
• 1Y: 29.23%
• 3Y*: 22.21%
• 5Y*: 12.97%
• 10Y*: 15.11%

FSKAX

• 1D: 0.27%
• 1M: 5.13%
• YTD: 11.81%
• 6M: 12.19%
• 1Y: 29.70%
• 3Y*: 22.32%
• 5Y*: 12.92%
• 10Y*: 15.07%

*Multi-year figures are annualized to reflect compound growth (CAGR)

BKTSX vs. FSKAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BKTSX iShares Total U.S. Stock Market Index Fund Class K	11.47%	17.15%	23.83%	26.02%	-19.05%	25.56%	20.82%	31.12%	-5.37%	21.02%
FSKAX Fidelity Total Market Index Fund	11.81%	17.06%	23.89%	26.12%	-19.53%	25.66%	20.79%	30.92%	-5.32%	20.85%

Correlation

The correlation between BKTSX and FSKAX is 1.00 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	1.00
Correlation (3Y) Calculated over the trailing 3-year period	0.99
Correlation (5Y) Calculated over the trailing 5-year period	1.00
Correlation (10Y) Calculated over the trailing 10-year period	1.00
Correlation (All Time) Calculated using the full available price history since Jan 5, 2016	1.00

The correlation between BKTSX and FSKAX has been stable across timeframes, ranging from 0.99 to 1.00 - a consistent structural relationship.

Return for Risk

BKTSX vs. FSKAX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

BKTSX

BKTSX Risk / Return Rank: 71
BKTSX Sharpe Ratio Rank: 71
BKTSX Sortino Ratio Rank: 64
BKTSX Omega Ratio Rank: 63
BKTSX Calmar Ratio Rank: 74
BKTSX Martin Ratio Rank: 82

FSKAX

FSKAX Risk / Return Rank: 71
FSKAX Sharpe Ratio Rank: 73
FSKAX Sortino Ratio Rank: 64
FSKAX Omega Ratio Rank: 64
FSKAX Calmar Ratio Rank: 74
FSKAX Martin Ratio Rank: 83

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

BKTSX vs. FSKAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Total U.S. Stock Market Index Fund Class K (BKTSX) and Fidelity Total Market Index Fund (FSKAX). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.

	BKTSX	FSKAX	Difference
Sharpe ratio Return per unit of total volatility	2.46	2.48	-0.02
Sortino ratio Return per unit of downside risk	3.35	3.36	-0.01
Omega ratio Gain probability vs. loss probability	1.44	1.44	0.00
Calmar ratio Return relative to maximum drawdown	3.35	3.38	-0.03
Martin ratio Return relative to average drawdown	15.42	15.57	-0.14
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BKTSX vs. FSKAX - Sharpe Ratio Comparison

The current BKTSX Sharpe Ratio is 2.46, which is comparable to the FSKAX Sharpe Ratio of 2.48. The chart below compares the historical Sharpe Ratios of BKTSX and FSKAX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	BKTSX	FSKAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.46	2.48	-0.02
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.75	0.75	0.00
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.82	0.82	0.00
Sharpe Ratio (All Time) Calculated using the full available price history	0.83	0.85	-0.03

Drawdowns

BKTSX vs. FSKAX - Drawdown Comparison

The maximum BKTSX drawdown since its inception was -34.97%, roughly equal to the maximum FSKAX drawdown of -35.01%. Use the drawdown chart below to compare losses from any high point for BKTSX and FSKAX.

Drawdown Indicators

	BKTSX	FSKAX	Difference
Max Drawdown Largest peak-to-trough decline	-34.97%	-35.01%	+0.04%
Max Drawdown (1Y) Largest decline over 1 year	-8.87%	-8.92%	+0.05%
Max Drawdown (3Y) Largest decline over 3 years	-19.29%	-19.43%	+0.14%
Max Drawdown (5Y) Largest decline over 5 years	-24.98%	-25.39%	+0.41%
Max Drawdown (10Y) Largest decline over 10 years	-34.97%	-35.01%	+0.04%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-4.53%	-4.02%	-0.51%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.93%	1.94%	-0.01%

Volatility

BKTSX vs. FSKAX - Volatility Comparison

iShares Total U.S. Stock Market Index Fund Class K (BKTSX) and Fidelity Total Market Index Fund (FSKAX) have volatilities of 2.94% and 2.97%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BKTSX	FSKAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.94%	2.97%	-0.03%
Volatility (6M) Calculated over the trailing 6-month period	9.14%	9.24%	-0.10%
Volatility (1Y) Calculated over the trailing 1-year period	12.17%	12.28%	-0.11%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.36%	17.41%	-0.05%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.41%	18.46%	-0.05%

BKTSX vs. FSKAX - Expense Ratio Comparison

BKTSX has a 0.02% expense ratio, which is higher than FSKAX's 0.02% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

BKTSX vs. FSKAX - Dividend Comparison

BKTSX's dividend yield for the trailing twelve months is around 1.04%, more than FSKAX's 0.93% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BKTSX iShares Total U.S. Stock Market Index Fund Class K	1.04%	1.14%	1.27%	1.46%	1.64%	1.58%	1.51%	2.15%	2.49%	2.17%	1.54%	0.00%
FSKAX Fidelity Total Market Index Fund	0.93%	1.01%	1.19%	1.41%	1.62%	1.15%	1.45%	1.94%	2.54%	2.07%	2.43%	0.82%

Frequently Asked Questions

Can I hold both BKTSX and FSKAX in my portfolio?

With a correlation of 1.00, BKTSX and FSKAX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, BKTSX or FSKAX?

FSKAX has higher volatility (2.97%) compared to BKTSX (2.94%). In terms of maximum drawdown, BKTSX dropped -34.97% vs FSKAX's -35.01%.

Which has better risk-adjusted returns?

FSKAX currently has the higher Sharpe Ratio (2.48 vs 2.46), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.